Angelman syndrome is a severe developmental brain disorder characterized by mental retardation, seizures, abnormal gait, hyperactivity, frequent laughter, and other abnormalities. Several lines of evidence strongly implicate the loss of the maternal human Ube3A (hUbe3A) gene in most, if not all, cases of Angelman syndrome. Ube3A encodes the E6-AP ubiqutin E3 ligase whose substrates remain largely unknown. How the loss of UbeSA activity leads to clinical symptoms of Angelman syndrome patients needs further investigation. In the Drosophila genome, the gene CG6190 encodes the Drosophila Ube3A (dUbeSA), a protein highly homologous to hUbeSA at the amino acid level. Therefore, Drosophila offers an excellent model system to dissect the molecular and cellular functions of Ube3A. Here we propose to test the hypothesis that UbeSA is required for the proper formation of neuronal fine structures and for the normal development of neuronal connectivity. The defects in these neurodevelopmental processes may contribute to the pathogenesis of Angelman syndrome. We will generate dUbeSA loss-of-function mutant flies and characterize dUbeSA function in neuronal development. We will also use these mutant flies to identify some evolutionary conserved key substrates of UbeSA ubiquitin ligase that mediate the effects of UbeSA on the brain development and function. These studies will provide important insights into the molecular and cellular mechanisms underlying this devastating developmental brain disorder and into the potential avenues for therapeutic interventions. Gladstone Institute of Neurological Disease, The J. David Gladstone Institutes, San Francisco, CA PHS 398 (Rev. 09/04) Page 2 Form Page 2 3 Principal Investigator/Program Director (Last, First, Middle): Gao, Fen-BiaO KEY PERSONNEL. See instructions. Use continuation pages as needed to provide the required information in the format shown below. Start with Principal Investigator. List all other key personnel in alphabetical order, last name first. Name eRA Commons User Name Organization Role on Project Fen-Biao Gao, Ph.D. fenbiao The j. David Gladstone institutes Principal Investigator Van Li, Ph.D. N/A The J. David Gladstone Institutes Postdoctoral Fellow Fay Wang, Ph.D. N/A The J. David Gladstone Institutes Postdoctoral Fellow OTHER SIGNIFICANT CONTRIBUTORS Name Organization Role on Project Human Embryonic Stem Cells [x] No D Yes If the proposed project involves human embryonic stem cells, list below the registration number of the specific cell line(s) from the following list: http://stemcells.nih.gov/reqistry/index.asp. Use continuation pages as needed. If a specific line cannot be referenced at this time, include a statement that one from the Registry will be used. Cell Line Disclosure Permission Statement. Applicable to SBIR/STTR Only. See SBIR/STTR instructions.Yes DNO PHS 398 (Rev. 09/04) Page 3 Form Page 2-continued Number the following pages consecutively throughout the application. Do not use suffixes such as 4a, 4b. 4 Principal Investigator/Program Director (Last, First, Middle): GaO, Fen-BiaO The name of the principal investigator/program director must be provided at the top of each printed page and each continuation page. RESEARCH GRANT TABLE OF CONTENTS Page Numbers Face Page J Description, [unreadable] [unreadable]